In recent years, antenna devices which use a conductive liquid as a radiating element have been attracting attention.
Since it is possible for a conductive liquid to operate as an antenna in any shape by flowing an electric current through the conductive liquid, a conductive liquid can be used as various types of antennas if an electric power can be fed in an efficient manner.
Conventional methods of feeding power to a conductive liquid include the following method.
Patent Document 1 described below discloses an antenna device in which a conducting wire is wound around a ring-shaped magnetic body and a current is passed through the conducting wire to generate a magnetic flux in the magnetic body. In the antenna device, by linearly ejecting a conductive liquid through a hole provided, in the ring-shaped magnetic body, power is fed to the conductive liquid due to magnetic field coupling.
Note that an operating frequency can be adjusted by controlling the ejection force of the conductive liquid and, accordingly, low-frequency communication can be performed without installing a large-size antenna.